Reinvestigation on species richness and environmental correlates of bryophytes at a regional scale in China

Aims The aim of this article is 4-fold: (i) to update species richness of bryophytes for each of the Chinese provinces based on the most current knowledge on distributions of bryophytes in China, (ii) to provide a set of analyses based on the updated species richness data and the environmental variables used in a recent article on species richness of bryophytes in China, (iii) to expand the analysis presented in the recent article by relating species richness of bryophytes to over 15 additional climatic variables and (iv) to determine the degree to which the relationships between bryophyte species richness and environmental variables that were reported in the recent article might have been biased. Methods Over 180 literatures with national, provincial and local species lists of bryophytes in China were used in this study. Taxonomy and nomenclature of bryophytes in China were standardized according to The Plant List. Correlation and regression analyses were used to examine the relationships between species richness or species density of bryophytes in Chinese provinces and environmental variables. Important Findings On average, each Chinese province possesses 700.6 species of bryophytes, which is 112.1 species more than previously reported. With the updated species richness data reported in this study, stronger relationships between species richness of bryophytes and environmental variables have been found, compared with those found in a recently published study for China. When single environmental variables were considered, precipitation-related variables were, on average, more strongly correlated with species richness and species density than were temperature-related variables. Environmental variables were on average correlated more strongly with species density than with species richness of bryophytes at the regional scale in China. Our study showed that measures quantifying the average and variation of environmental conditions within each Chinese province explained 82.7% and 71.1% of the variation in species richness of liverworts and mosses, respectively, and explained 86.5% and 70.7% of the variation in species density of liverworts and mosses, respectively.